Question: What do the following two equations represent? $-4x-2y = -3$ $10x-20y = -4$
Answer: Putting the first equation in $y = mx + b$ form gives: $-4x-2y = -3$ $-2y = 4x-3$ $y = -2x + \dfrac{3}{2}$ Putting the second equation in $y = mx + b$ form gives: $10x-20y = -4$ $-20y = -10x-4$ $y = \dfrac{1}{2}x + \dfrac{1}{5}$ The slopes are negative inverses of each other, so the lines are perpendicular.